Convertible bed



S. C. WILLIS CONVERTIBLE BED July 11,1961

2 Sheets-Sheet 1 Filed Oct. 31, 1957 INVENTOR SUMNER C. WILL/5 y 1951 s. c. WILLIS 2,991,484

CONVERTIBLE BED Filed Oct. 51, 1957 g s s g I d 4Z INVENTOR 72% SUMNER c. WILL/5 ATTORNEY5 United States PatentQ 2,991,484 CONVERTIBLE BED Sumner C Willis, White Plains, N.Y., assignor to Castro Convertible Corporation, New Hyde Park, N.Y., a corporation of New York Filed Oct. '31, 1957, Ser. No. 693,637 13 Claims. (Cl. 5-13) of this kind which easily and automatically locks itself rigid in either open or closed position.

A further object is to provide a convertible bed mechanism which does not require critical tolerances in manufacture and which can be mass produced at relatively low cost with uniformly excellent quality.

These and other objects will in part be pointed out in and in part understood from the following description.

One popular type of a sofa-bed at the present time .is known in the trade as a longboy. In a longboy type sofa-bed; when unfolded into the bed position the occupant sleeps with his head near one arm of the sofa and his feet near the other arm. Such a unit usually has three sections supported on swinging links from a stationary frame and arranged to be extended in a straight line out from the frame to support a mattress and make a bed, the longest dimension of which is parallel to the frame. Alternatively these sections can be folded in sofa position the frame, the end section being doubled back over the inner section, to form a supporting platform for sofa seat cushions.

It is essential that the opening and closing actionof any such bed mechanism should be smooth and effortless and that in either open or closed position the pivoted sections of the mechanism should be rigidly held in place.

Failure to provide such rigidity results in a product which is neither a comfortable bed nor a comfortable sofa. Designers of previous sofa beds have attempted to solve this problem by providing various arrangements to inter-engage the bed sections and hold them rigid.

.Some of these arrangements were manually actuated locks and, though relatively simple, were often inconvenient to use and often quite unmanageable. Other locks, though more nearly automatic, were very complicated and had to be made to close tolerances so that they were readily vulnerable to abuse or even normal wear. The present invention in one of its aspects provides a greatly improved locking arrangement in answer to this problem.

A most important factor in promoting the acceptance by the public of sofa beds is the feasibility of styling them to look exactly like ordinary sofas. This question of styling is now being accentuated of course by the modern trend toward slimmer and more streamlined furniture. Many previous convertible bed mechanisms, because of their complexity and unwieldliness, imposed a box-like appearance on the enclosing furniture frame. In the past, some people who would otherwise buy a sofa-bed to have in their homes as an occasional or extra bed, simply refused to buy one because its look was ungainly and it clearly revealed its double purpose, or because its style was of necessity out of keeping with their other furniture. The present invention provides a Patented July 11, 1961 multi-section bed mechanism which is greatly simplified and very streamlined in comparison with previous mechanisms and which therefore lends itself to the most modern otf-the-fioor sofa styles. Even though this mechanism has fewer parts than prior mechanisms, it is sturdy and sag-free, especially in sofa position. In actual fact, a sofa-bed constructed according to the invention is virtually indistinguishable in appearance and comfort from a most elegant and stylish conventional sofa.

People who buy sofa-beds demand not only a structure of pleasing aesthetic appearance but also one which can be operated easily and which is always reliable. It is highly aggravating, especially to a person who has invested his money in a sofa bed, for the bed mechanism to refuse to fold or unfold properly or to tear and rip the bed linen. Previous bed mechanisms sometimes were prone during folding or unfolding to catch or pinch blankets and sheets and either jam themselves to a stop or else to inexorably move on to final position grinding up and ruining the sheets, blankets or whatever else was "caught. The present invention provides a =sofa-bed mechanism which minimizes this difiicu-lty. Those elements which in previous mechanisms were most likely to become entangled with the bed linen have been eliminated and replaced by a simple and most effective linkage. During folding of this bed mechanism, the outer or end section is drawn back, down, and over the inner section thereby compressing the mattress between them with a powerful squeezing action. When the bed is finally folded, the end section, upon which the sofa seat cushions rest, is securely held against movement, either upward or downward, and in exact position within the furniture flame so that the seat cushions can be placed upon the folded mechanism at the proper height and angle to make a comfortable sofa.

In accordance with one aspect of the present invention there is provided a basic convertible bed mechanism having three sections serially pivoted to each other and interconnected by a unique operating linkage. These sections are supported in a stationary furniture frame and are adapted to fold or unfold to the alternative positions described above. The two right angle corners,

formed at the front part of the sofa by the three secare inherently free of the more serious causes of wear.

They are not prone to jamming or failure to operate because of mis-alignment.

A better understanding of the invention together with a fuller appreciation of its many advantages will be gained from the following description given in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view, partly in cross-section, of'a sofa-bed embodying features of the invention;

FIGURE 2 is a perspective view of one side of the operating mechanism and frame of the bed seen in FIG- URE 1 and shown here completely unfolded into its bed position;

FIGURE 3 is a view similar to FIGURE 2 but showing the mechanism just after the folding into its sofa position has begun;

FIGURE 4 is a view of the bed mechanism more early closed than in FIGURE 3; e

FIGURE 5 is a view of the mechanism shown nearly completely folded;

FIGURE 6 is a side view of the mechanism completely folded; and

FIGURE 7 is an enlarged view of one of the corner portions shown in FIGURE 6.

The sofa bed 10 seen in FIGURE 1,, shownfolded but with its unfolded position indicated by the broken .lines 11, comprises a stationary frame 12 in which is suspended a mattress supporting mechanism, generally indicated at 14. Removably positioned on top of this mechanism are the seat cushions 16 whose rear edge abuts a back cushion 18 permanently affixed to the frame. Lying in front of this cushion are the removable pillows 19. Doubled back upon itself within the folded mechanism 14 is a mattress 20 (shown dotted) which, when the bed is opened as indicated by the broken ,lines, is supported a convenient distance above the floor by the unfolded bed mechanism.

The width and length of the mattress and its supporting mechanism are proportioned so that two persons can sleep on the bed lying along the direction of the double arrow 22, i.e. parallel to the length of frame 12.

As seen in FIGURE 2, wherein the bed is shown unfolded with parts broken away and with the mattress and the frame upholstery omitted, the bed mechanism 14 includes three sections serially pivoted together. The innermost of these sections, inner section 24, is suspended for outward and upward movement to the position shown by a rear swing link 26 pivoted at 28 to section '24 and pivoted at 30 to a bracket 32 fastened to stationary frame 12. The forward end of section 24 is suspended from frame 12 by a front swing link 34 pivoted at 36 to a tab 38 attached to section 24, the lower end of link 34 being pivoted at 40 to a strap 41 fastened to frame 12.

Serially pivoted to the front end of inner section 24 at 42 is the second or connecting section 44, to which in turn is pivoted at 46 the third or end section 48. The three sections 24, 44 and 48, as seen in FIGURE 2, when unfolded extend horizontally in line outward from frame 12 and are adapted to support the mattress (not shown here) on the taut bed spring 50 which is attached within these sections along their edges.

End section 48 is supported horizontally above the floor by the two legs 52 and 54 pivoted to it at points 56 and 58 respectively. Connecting section 44 is supported solely by its attachment to the sections on either end of it, and inner section 24 is supported by links 26 and 34. To prevent the rear end of section 24 from sagging under a load, link 26 in the position of FIG- URE 2 is locked against clockwise rotation about its pivot 30 by the rearward thrust of the long link 59 which is pivoted to link 26 at point 60 just above its pivot 28. Weight resting on the rear of section 24 is transmitted through pivot 28 to link 26 and tends to rotate it clockwise about pivot 30. This is resisted however by the thrust of link 59 against pivot 60 which develops an equal and opposite moment of force on link 26 about pivot 28. Downward force on the forward end of section 24 similarly tends slightly to rotate 'link 34 clockwise about its pivot 40 but since link 26 cannot rotate clockwise beyondthe position shown, neither can link 34.

The forward end of link 59 is pivoted at 62 to the upper portion of the short pivoted crank-arm 64, whichin FIGURE 2 extends vertically downward below the point 66 at which it is pivoted to section 24. Forward thrust of link 59 against pivot 62 tends to rotate arm 64 clockwise around pivot 66 but this in turn is resisted by a forward pull on the lower end of arm 64 by the articulated linkage 68 pivoted to it at 70. Linkage 68, which comprises two short lengths 72 and 74 pivoted together at 76 and extending generally in line, pulls "against its own forward pivot point '78 on the rigid plate or corner member 80. The latter at its upper end is pivoted at 82 to end section 48 and forms in conjunction with links 72 and 74 a folding and locking means for the bed.

The pull by linkage 68 on corner 80, which pull tends to rotate it clockwise about pivot 82, is resisted by a counter thrust on the pin 84 carried by corner above pivot 82. Pin 84 rides in a slot 88 in the rear end of the link 90 and in the position of FIGURE 2 abuts the front end of the slot thus preventing clockwise rotation of corner 80.

As seen perhaps even more clearly in FIGURE 3, the forward end of link 90 is pivoted, in common with the link 92, at point 94 to the long link 96. The rear end of the latter is pivoted at 98 to connecting section 44 and the forward end of this link 96 is pivoted at 100 to leg 52. At the beginning of folding of the bed as seen in FIGURE 3, end section 48 is manually lifted from the floor and pivots around its point of attachment 46 to connecting section 44. This causes link 96 to shift forward relative to end section 48 and in so doing to fold the legs 52 and 54, the latter being controlled through link 92 which is pivoted to it at 93. Leg 52 stops against link 92 when fully folded as seen in FIGURE 4.

Folding of the bed continues beyond the position of FIGURE 3 to that of FIGURE 4 wherein end section 48 is disposed approximately at right angles to connecting section 44 and wherein section 44 is being brought up toward right-angle relation with inner section 24. This last section may by now be shifted slightly back into the frame so that the short arm 64 has begun to rotate clockwise about point 66. In so doing this arm, pulling on linkage 68, with great force draws the uppen flange 102 of solid corner 80 gradually into extended contact with end section 48 and also, see FIGURE 5, draws the front or lower flange 104 of corner 80 into contact with connecting section 44. This forces the connecting section to be generally perpendicular to both the end and the inner sections. The mattress (not shown here) is compressed and folded double upon itself and the end and connecting sections are held with complete rigidity in folded position relative to the inner section. Because of the powerful drawing together of these sections from the position of FIGURE 4 to that of FIGURE 5 produced by the action of corner 80, in turn caused by the clockwise rotation of arm 64 upon movement of section 24 back and down within frame 12, a person closing the bed is saved the strenuous effort of pushing the end section into fully folded relation above the inner section against the resistance of the doubled-over mattress.

To complete the folding of the bed, the now folded sections 24, 44 and 48 shown in FIGURE 5 are lowered as a rigid unit from this position to that of FIGURE 6 wherein they are fully seated within frame 12. Their weight is largely counterbalanced by the springs 105 fixed to the end of strap 41 at 106 and connected at 107 to front swing link 34 to be stretched when this link swings counterclockwise i.e. from the position of FIGURE 5 to that of FIGURE 6, about its pivot 40. Even though during this final folding the short arm 64 continues to rotate from the position of FIGURE 5 clockwise into side-byside relation with section 24 as shown in FIGURE 6, the inward and downward pulling movement of linkage 68 against corner 80 ends when the mechanism in folding from the position of FIGURE 4 reaches the position of FIGURE 5. Here, arm 64 is parallel with linkage 68, the lower portion 72 of the linkage lying side-by-side along arm 64 with pivot 76 lying generally opposite and on the same axis with pivot 66. As arm 64 continues to rotate clockwise from the position of FIGURE 5 to that of FIGURE 6, the raised flap or abutment 108 (see also FIGURE 4) integral with it bears against the top side of the lower portion 72 of linkage 68. This rotates portion 72 in unison with arm 64 around its pivot 66 and the linkage pivot 76, which two pivots in all positions between FIGURES 5 and 6 have effectively a common axis. As a consequence, the tension force developed in the upper portion 74 of linkage 68 can be brought to a maximum in the position of FIGURE 5 and thereafter be maintained without further increase even though the lower pivot point 70 of the linkage moves past the line of centers of points 76 and 78. Thus the very desirable selflocking action of a toggle is obtained but without encountering an excessive and possibly destructive build-up and then wasteful decrease in the link tension as the pivots move past center. To insure that connecting section 44 will come to generally right-angle relation with inner section 24 and then stop and stay rigid under the tension of linkage 68, the lower end of connecting section 44, as seen in FIGURE 7, has a toe portion 109 which butts against section 24 to the rear of their common pivot 42.

When the bed is in the position of FIGURE 6, the rear end of section 24 is suspended by rear swing link 26 which is now downwardly extending and slightly back past vertical. The weight of the front end of the bed is borne .by corner 80 which in turn is rigidly bolted to the frontboard 110, see also FIGURE 1, the lower edge of the latter resting upon the transverse rail or cross-brace 112 fixed to the lower front edge of frame 12. Since no .play or sagging of the bed sections relative to each other is allowed by corner 80 and linkage 68, these sections are held almost as rigid relative to each other and frame 12 as though they were welded in this position.

. They therefore provide a steady, comfortable and sagless support for the sofa cushions.

While not necessary, an auxiliary support beneath the inner end of folded end lsection 48 can be provided in the form of the strut 114 fixed at each of its ends to a rear swinglink 26 on each side of the mechanism. This strut is positioned so that when the bed is folded, the tapered end 116 of the end j section rests upon it.

As seen in FIGURE 6, the top surface of the inner or rearrnost end of folded end section 48 is spaced at 118 by only a very short distance beneath the lower edge of the stationary back cushion 18. The leaving of such a small clearance here is possible because the end section even before the bed is finally closed has already been 4 drawn down fully relative to the inner section. Accordingly, this top end moves substantially only horizontally backward during the final seating of the mechanism within frame 12. Also, since the end section 48 is sorigidly held relative to inner section 24, practically no allowance here for up and down play of the end section is necessary, even without transverse strut 114.

The left side of the bed mechanism (shown herein) is rigidly joined or tied to the right side (not shown, but a mirror image of the left) by several transversely extending members. A first of these, seen in FIGURE 2, is riveted to the forward-most end of end section 48 and comprises the hollow round tube 120 whose own end is flattened at its point of attachment to section 48. In addition, riveted to the lower end of short arm 64 is a second transverse tube 122 similar to tube 120. A third transverse'member, riveted near the center of connecting section 44, is the flanged channel 124 which while providing torsional rigidity also supports bed spring 50 along the longitudinal centerline of the mattress when the bed is open. This isolates to a certain extent the two halves of the bed and provides greater sleeping comfort for two people.

A fourth transverse member is provided at the rear of inner side of the bed and comprises the rail 126 which is welded to the rear end of inner section 24. Channel 124 lies equidistant from this rail 126 and the front transverse member, tube 120. These members, and tube 122, provide great transverse rigidity and insure that both sides of the bed move in unison in opening or closing.

As seen only in FIGURE 2 there is resiliently fastened to the top end of corner 80 at l30 and stretched to extend just behind along the top edge of frontboard 110, a fiexible sheet 132 of a suitable padded materiaL, .Whenthe;

bed is folded '(se'e'FIGURB'4) this-sheet serves'tocover springs 50 and to protect and support the seat cushions. the forward end of sheet 132 extends around transverse tube 120 and is fastened to the springs. Thegener-al way this sheet is attached to the bed mechanism and 'the:position it has when the bed is'folded are completely described in US. Patent No. 2,752,613. w

It will now be apparent that the bed mechanism described herein is simplified in design and streamlined'in appearance relative to previous bed mechanisms. Fewer parts are needed in this mechanism and this means an appreciable savings in cost and a reduction in weight. Even so, the mechanism is exceptional in case of operationand in freedomfrom sag, especially when in sofa position. The mechanism folds compactly within the stationary frame and makes utmost use of the space available. Thus, off-the-floor sofa styles, such as that illustrated, are permitted but yet the seat cushion platform (i.e. end section 48) when the bed is folded will lie at the proper height for best seating comfort; The width of the seat cushions can easily be made small enough for comfort without excessive space behind the back cushion, and the pitch of the seat platform can be slightly downward and back, as in a conventional sofa. No large and wasteful internal spaces or clearance gaps between frame and mechanism are required to permit FIGURES 2 through 6 of the drawings were made from photographs of an actual bed mechanism and they show substantially exactly the relative sizes, shapes and positions of the various parts and elements.

The invention described herein is not limited to use solely with a three-section sofa-bed. In some instances it may be desirable to lengthen the lower end of crankarm 64 so that it serves also as a support leg. The description of the invention given herein is intended in illustration and not in limitation of it. Various changes or modifications in the structure described may occur to those skilled in the art and these can be made without departing from the spirit or scope of 'the invention as set forth.

I claim:

1. In an improved sofa bed mechanism: an inner section, a connecting section, an end section, said sections being pivoted serially together and adapted when folded to lie with the inner section generally horizontal, the end section generally parallel above it and with the connecting section generally vertical and perpendicular to said inner and end sections, and when unfolded being adapted to lie generally horizontally in a straight line, support means connected to said mechanism to retractably suspend it from a stationary frame, an arm-like member pivoted at a first point to said inner section near its forward end,

means for swinging said arm-like member downward and forward to generally perpendicular relation with said inner section when said sections are unfolded and backward and up beneath or alongside said inner section when said 1 sections are folded, a first short link pivoted to the lower end of said arm-like member at a second point, a second short link pivoted to said first link at a third point, the distances between said first and second points and between said second and third points being substantially equal, a corner linkage extending between said second link to a fourth pivot point on said end section forward of its rear end, said short links and corner linkage and said arm-like member when said sections are folded acting to hold said sections rigid, said corner linkage engaging said connecting section when said sections are folded and being adapted to swing forward and downward out of engagement with said connecting section when said sections are unfolded, said first and third pivot points lying substantially opposite each other when said sections are folded, and at least one leg pivoted to said end section and adapted when said sections are unfolded to extend down to support said end section horizontally above the floor.

.2. The structure as in claim 1 wherein said corner linkage comprises a rigid member having atop flange and a front or lowerflange adapted to bear against said end and connecting sections respectively when said sections are folded, said flanges being at right angles to each other, said rigid member being directly ,pivoted to said second short link.

3. The structure as in claim 2 in further combination with means tending .to rotate saidrigid corner member to tension said short links when said sections are unfolded.

4. The structure as in claim 1 wherein said arm-like member carries .an abutment which bears against said first short link to move it in unison with said arm memher when said sections are folded and said arm-like:memher is brought up against said inner section.

5. An improved sofa bed comprising: a stationary frame; an inner section; a connecting section pivoted to the front end of said inner section; an end section pivoted to the front end of said connecting section; a bed spring stretched within said section to support .a mattress; said sections when folded lying 'within said frame with the inner section closely above the floor, the end section lying folded back over and generally parallel above the inner section and with the connecting section lying approximately vertical at the front of said frame and generally perpendicular to said inner and end sections, the mattress being compressed double within said sections; said sections when unfolded extending in line outward from said frame horizontally above the floor to support the mattress in bed position; and elements on each side of said sections, the elements on one side being the mirror image of those on the other, said elements including a front swing link and a rear swing member, each pivoted between one side of said frame and said inner section, a crank-arm member pivoted at a first point to said inner section near its forward end and having a lower portion which extends down when said sections are unfolded, means for rotating said crank-arm backward and toward said inner section as said sections are moved into said frame and vice-versa, a first short link pivoted to the lower end of said crank-arm, a second short link pivoted at a second point to said first short link, an abutment means to move said crank arm and said first short link in unison as said crank-arm is rotated backward, said first and second points having effectively the same axis when said crank-arm moves in unison with said first short link, a rigid corner member pivoted at its inner or lower end to said second short link and pivoted at its upper end to said end section at a third point lying forward of 'its rear end, a frontboard rigidly mounted on the front face of said corner member, a first leg pivoted to said end section near its front end and having an upward extending tab, a leg-actuating link pivoted between said connecting section and said tab to fold said leg when said sections are folded, and means to prevent said inner and connecting sections from folding together substantially more than a right angle.

6. The structure as in claim 5 wherein said means for rotating said crank arm comprises a long push link pivoted at its rear to said rear swing member, said rear swing member being pivoted to the rear end of said inner sec tion, the forward end of said long push link being pivoted to said crank-arm at a point above said first point, and in further combination with means for preventing backward rotation of said crank-arm when said sections are unfolded, said means including a link pivoted to said rigid corner member above said third point and to said leg-actuating link at a fourth point forward of said third point.

7. The structure as in claim 6 in further combination with a second leg pivoted to said end section near its rear end and a short leg link pivoted to said second leg and to said leg-actuating link at said fourth point, said first leg stopping against said short leg link when said legs are folded.

8. The structure as in claim 5 wherein said rigid corner member is a plate having a top shoulder to engage said end section and a front shoulder to engage said connecting section to hold them at right angles.

9. An improved convertible bed mechanism comprising: an inner section, a connecting section and an end section serially pivoted together and being adapted to fold and unfold, a rotatable member pivoted to said inner section near its forward end at a point number one and adapted to extend generally downward when said sections are unfolded, said sections being adapted to be movably suspended within a furniture frame, means to rotate said rotatable member downward and forward when said sections are unfolded, and backward and upward when said sections are folded, and folding and locking means pivoted at one end at a point number two to said end section and pivoted at its other end at a point number three to said rotatable member near the lower end thereof, said point two being the only direct pivot between said folding and locking means and said inner and end sections, said folding and locking means being bendable at a point number four, the distance between points three and four being generally equal to the distance between points one and three, said points one and four being adapted to move into generally side-byside relation during folding of said mechanism and 'to remain in said relation upon further backward rotation of said rotatable member, said folding and locking means serving to draw said sections with great force into generally perpendicular relation with each other when said rotatable member is rotated backward.

10. In an improved sofa bed mechanism: an inner section, a connecting section, an end section, said sections being pivoted serially together and adapted when folded to lie with the inner section generally horizontal, the end section generally parallel above it and with the connecting section generally vertical and perpendicular to said inner and end sections, and when unfolded being adapted to lie generally horizontally in a straight line, a front swing link and a rear swing member connected to said mechanism to suspend it from a stationary frame, an arm-like member pivoted at a first point to said inner section near its forward end, a long link pivoted to said rear swing member and to said arm-like member for swinging said arm-like member downward and forward to generally perpendicular relation with said inner section when said sections are unfolded and backward and up beneath or alongside said inner section when said sections are folded, an articulated linkage pivoted to said arm-like member near the lower end thereof at a second point, a rigid corner link pivoted to said articulated linkage and to said end section, said articulated linkage lying beneath and generally parallel to said sections when unfolded, at least one leg pivoted to said end section and adapted when said sections are unfolded to extend down to support said end section horizontally above the floor, and means acting on said rigid corner link when said sections are unfolded and in conjunction with said long link to hold said articulated linkage taut.

11. An improved convertible bed mechanism comprising: at least three folding sections including an inner section, a connecting section and an end section serially pivoted together and being adapted to fold and unfold, a rotatable member pivoted to said inner section near its forward end at a point number one and adapted to extend generally downward when said sections are unfolded, said sections being adapted to be movably suspended within a furniture frame, means to rotate said rotatable member downward and forward to generally perpendicular relation with said inner section when said sections are unfolded, and backward and upward when said sections are folded, a rigid member connected at one end by a pivot pin to said end section slightly forward of the nect n between said end section and said connecting section, and articulated linkage means pivoted adjacent one end at a point number two adjacent the other end of said rigid member and pivoted adjacent its other end at a point number three to said rotatable member, said linkage means near its midpoint being bendable at a point number four, the distance between points three and four being generally equal to the distance between points one and three, said points one and four being drawn into generally side-by-side relation by initial backward rotation of said rotatable member upon partial folding of said mechanism and effectively remaining in said relation upon further backward rotation of said rotatable member, said articulated linkage means serving to draw said sections with great force into generally perpendicular relation with each other when said rotatable member is rotated backward and said points one and four move toward side-by-side relationship.

12. In a bed mechanism having at least three sections: an inner section, a connecting section and an end section serially pivoted together and being adapted to fold and unfold, a rotatable member pivoted to said inner section near its forward end at point number one and adapted to extend downward when said sections are unfolded, means to suspend said sections Within furniture frame, means to rotate said rotatable member downward and forward when said sections are unfolded, and backward and upward when said sections are folded, a first short link, serial link means pivoted at one end to said end section adjacent its rear end and pivoted at its other end only to one end of said first short link at point number two, the other end of said short link being pivoted to the lower end of said rotatable member, the length of said short link being such that when said sections are folded and with said short link parallel alongside said rotatable member, pivot point number one lies substantially opposite pivot point number two, means for holding pivot points one and two substantially opposite each other upon further rotation of said rotatable member after said sections have reached substantially perpendicular relation to each other, said serial link means serving to draw said sections into generally perpendicular relation with each other when said rotatable member is rotated backward, the upper portion of said serial link means and said end and connecting sections being held rigid relative to each other by the force of said first short link as soon as point one moves opposite point two during the folding of said bed.

13. The structure as in claim 12 wherein said serial link means includes a rigid approximately triangular corner plate pivoted at its upper end to said end section, and a second short link pivoted at its forward end to said plate and at its rear end to said first short link at pivot point number two.

References Cited in the file of this patent UNITED STATES PATENTS 1,527,416 Konrad Feb. 24, 1925 2,582,904 Harmon Jan. 15, 1952 2,584,145 Martin Feb. 5, 1952 2,634,428 Fox Apr. 14, 1953 2,721,337 Bank ,et a1. Oct. 25, 1955 2,770,814 Schindler Nov. 20, 1956 2,807,031 Fox Sept. 24, 1957 2,832,965 Pokorny May 6, 1958 

